Conventional optical communication networks include, for example, gigabit passive optical networks (GPONs). The characteristics of exemplary GPONs are described in ITU-T Recommendations G.984.1, G.984.2 and G.984.3, which are incorporated by reference herein. In a typical GPON system, an optical line terminator (OLT) associated with a central office communicates with multiple optical network units (ONUs) corresponding to respective customers. In such a system, data may be transmitted at various data rates up to 2.5 Gigabits per second (Gbps) in a downstream direction, from the central office to the customers, and in an upstream direction, from the customers to the central office. A given system may be symmetrical or asymmetrical in terms of the particular data rates used in the respective downstream and upstream directions, that is, the overall downstream and upstream data rates may be same or different. GPONs provide an efficient mechanism for provision of high-bandwidth services in a local loop. Such services may include, for example, streaming video, Internet access, IP television (IPTV) and IP telephony.